Add Cloudflare email and collaboration workflows

apps/server/internal/email/queue.go

@@ -3,6 +3,7 @@ package email
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 	"log/slog"
 	"math"
@@ -211,17 +212,28 @@ func (q *Queue) deliver(ctx context.Context, row QueueRow) error {
 	}
 
 	// Failure: retry or give up.
-	if row.Attempts >= row.MaxAttempts {
+	var permanent *PermanentError
+	if errors.As(err, &permanent) {
+		if _, ferr := q.db.ExecContext(ctx, `
+			UPDATE email_queue SET status = 'failed', last_error = ? WHERE id = ?
+		`, truncateErr(err.Error()), row.ID); ferr != nil {
+			return fmt.Errorf("mark permanent failure: %w", ferr)
+		}
+		q.logger.Warn("email permanently rejected", "id", row.ID, "attempts", row.Attempts+1, "error", err)
+		return nil
+	}
+	currentAttempt := row.Attempts + 1
+	if currentAttempt >= row.MaxAttempts {
 		if _, ferr := q.db.ExecContext(ctx, `
 			UPDATE email_queue SET status = 'failed', last_error = ? WHERE id = ?
 		`, truncateErr(err.Error()), row.ID); ferr != nil {
 			return fmt.Errorf("mark failed: %w", ferr)
 		}
-		q.logger.Warn("email permanently failed", "id", row.ID, "attempts", row.Attempts, "error", err)
+		q.logger.Warn("email permanently failed", "id", row.ID, "attempts", currentAttempt, "error", err)
 		return nil
 	}
 
-	backoff := q.backoff(row.Attempts)
+	backoff := q.backoff(currentAttempt)
 	next := time.Now().UTC().Add(backoff)
 	if _, err := q.db.ExecContext(ctx, `
 		UPDATE email_queue SET status = 'pending', next_attempt_at = ?, last_error = ? WHERE id = ?
@@ -229,9 +241,9 @@ func (q *Queue) deliver(ctx context.Context, row QueueRow) error {
 		return fmt.Errorf("schedule retry: %w", err)
 	}
 
-	// TemporaryError (Postmark 5xx) is retried with the same backoff as
-	// other errors; the max-attempts cap still bounds total work.
-	q.logger.Info("email retry scheduled", "id", row.ID, "attempt", row.Attempts, "backoff", backoff, "error", err)
+	// Temporary provider failures and unclassified sender failures are retried;
+	// PermanentError is handled above without wasting additional attempts.
+	q.logger.Info("email retry scheduled", "id", row.ID, "attempt", currentAttempt, "backoff", backoff, "error", err)
 	return nil
 }